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Malfunction Indicator Lamp
Service Engine Soon Light
If this light comes on or
flashes while you are
driving, two things may
happen.
First, you will not notice any difference in engine
performance, but your tail pipe emissions may increase.
Second, your engine may not run properly or may
stall without warning. If either of these things happen,
drive or tow your vehicle to your dealer for service.
This light should come on when the ignition is on, but
the engine is not running, as a check to show you
it is working. If it does not come on at all, have
it repaired.
Notice:If you keep driving your vehicle with this
light on, after awhile, your emission controls
may not work as well, your fuel economy may not
be as good, and your engine may not run as
smoothly. This could lead to costly repairs that may
not be covered by your warranty.
Oil Pressure Gage
The engine oil pressure gage, on the lower right portion
of your instrument panel cluster, shows engine oil
pressure in psi (pounds per square inch) or in kPa
(kilopascals). Oil pressure may vary with outside
temperature and oil viscosity, but readings of
30 to 40 psi (205 to 275 kPa) on gasoline engines at
operating temperature and moderate road speeds
are normal. If you have a diesel engine, the normal
operating range should be between 35 and 70 psi
(240 to 480 kPa).
United StatesCanada
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Page 255 of 398

•SAE 15W-40
As shown in the viscosity chart, SAE 15W-40 is
best for your vehicle. However, you can use
SAE 10W-30 at temperatures above 0°F (−18°C).
When it is very cold, below 0°F (−18°C), you should
use SAE 5W-40 to improve cold starting. 5W-40
is not recommended for use at high temperatures,
above 100°F (38°C).
These numbers on the oil container show its
viscosity, or thickness. Do not use other viscosity
oils such as SAE 10W-40 or SAE 20W-50.
This doughnut-shaped
logo (symbol) is used on
most oil containers to
help you select the correct
oil. It means that the oil
has been certified by
the American Petroleum
Institute.
You should look for this on the oil container, and use
onlythose oils that display this logo.
GM Goodwrench
®oil of the recommended viscosity
grades meets all the requirements for your vehicle.
Engine Oil Additives
Do not add anything to your oil. The recommended oils
with the API service symbol are all you will need for
good performance and engine protection.
When to Change Engine Oil (Vehicles
Without the Engine Oil Life System)
If you have the 6.6L V8 (LLY) Engine: Change engine
oil and filter every 15,000 miles (24 000 km), or
every 12 months, or every 750 hours of engine
operation, whichever occurs first. If you have the
7.8L V6 (LG4) Engine: Change engine oil and filter
every 12,000 miles (20 000 km), or every 12 months, or
every 600 hours of engine operation, whichever
occurs first. SeeScheduled Maintenance on page 6-5.
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Page 258 of 398

What Kind of Engine Oil to Use
Look for two things:
•GM6094M
Your vehicle’s engine requires oil meeting GM
Standard GM6094M. You should look for and use
only an oil that meets GM Standard GM6094M.
•SAE 5W-30
As shown in the viscosity chart, SAE 5W-30 is best
for your vehicle.These numbers on an oil container show its
viscosity, or thickness. Do not use other viscosity
oils such as SAE 20W-50.
Oils meeting these
requirements should also
have the starburst
symbol on the container.
This symbol indicates
that the oil has been
certified by the American
Petroleum Institute (API).
You should look for this information on the oil container,
and useonlythose oils that are identified as meeting
GM Standard GM6094M and have the starburst symbol
on the front of the oil container.
Notice:Use only engine oil identi ed as meeting
GM Standard GM6094M and showing the American
Petroleum Institute Certi ed For Gasoline Engines
starburst symbol. Failure to use the recommended
oil can result in engine damage not covered by
your warranty.
GM Goodwrench®oil meets all the requirements for
your vehicle.
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Page 367 of 398

Part C: Recommended Fluids
and Lubricants
Fluids and lubricants identified below by name, part
number, or specification may be obtained from
your dealer.
Usage Fluid/Lubricant
Engine Oil
(Gasoline
Engine)Engine oil which meets GM
Standard GM6094M and displays
the American Petroleum Institute
Certified for Gasoline Engines
starburst symbol. GM Goodwrench
®
oil meets all the requirements for
your vehicle. To determine the
proper viscosity for your vehicle’s
engine, see “Engine Oil” in the
Index.
Engine Oil
(DURAMAX
®
Diesel Engine)Engine oil with the letters CI-4 or
CH-4 is best for your vehicle. The
CI-4 or CH-4 designation may
appear either alone or in
combination with other API
designations, such as API CI-4/SL.
These letters show American
Petroleum Institute levels of quality.
To determine the preferred viscosity
for your vehicle’s diesel engine, see
“Engine Oil” in the Index.
Engine Oil
(Caterpillar
®
Diesel Engine)See the Caterpillar
®Operation &
Maintenance Manual for engine oil
recommendations.
Usage Fluid/Lubricant
Engine Coolant
(Caterpillar
®
Diesel Engine)See the Caterpillar
®Operation &
Maintenance Manual for engine
coolant recommendations.
Engine Coolant
(Gasoline
Engine &
DURAMAX
®
Diesel)50/50 mixture of clean, drinkable
water and use only DEX-COOL
®
Coolant. SeeEngine Coolant
(Gas and DURAMAX®Engines) on
page 5-38orEngine Coolant
(Caterpillar
®Diesel Engines) on
page 5-40.
Hydraulic Brake
SystemDelco
®Supreme 11 Brake Fluid or
equivalent DOT-3 brake fluid.
Windshield
Washer SolventGM Optikleen
®Washer Solvent.
Clutch Bearing
LubricantClutch Bearing Lubricant
(GM Part No. 12378484 or
equivalent NLGI #3 consistency).
Exhaust Brake
Ball Joint Cap
LubricantHigh-Temperature Grease
(GM Part No. U.S. 1051344, in
Canada 903037) or NLGI #3
consistency.
Power Steering
SystemDEXRON
®-VI Automatic
Transmission Fluid.
Manual
Transmission
(Except ZF
6-Speed)Synthetic Manual Transmission Fluid
(GM Part No. U.S. 12345724, in
Canada 10953510).
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